INDIANAPOLIS (AP) - A state-funded research pact between Indiana's top two state universities has yielded its first fruit - a human clinical trial that will test a promising new therapy for spinal cord injuries.

Purdue University and Indiana University say the Food and Drug Administration has cleared them to test on humans an implantable device that harnesses electrical fields to stimulate nerve growth in damaged spinal cords.

By year's end, the first patients taking part in the project will undergo surgery to implant the device above their spinal injuries.

The hope is that by feeding weak electrical fields into the wound, the device will spur nerve growth, healing the spinal cord enough to allow the test subjects to regain at least some feeling and movement.

As a phase one clinical trial, the test is aimed only at assessing whether the device is safe to use in humans.

But the Indiana University School of Medicine researchers who will conduct the trial as part of the Purdue-IU partnership said they are hopeful it will have some therapeutic effect.

"Something will happen, the question is how robust the response will be. We'll just have to wait and see," Scott Shapiro, a professor of neurosurgery at the IU School of Medicine, said during a recent announcement of the study.

Shapiro, who will oversee the clinical trial, said it will be about a year before the results are made public.

Under the study's rigid criteria, patients must enter the trial within 18 days from the time of their injury because tests on dogs showed the stimulator worked only on canines treated within two weeks of injury.

Patients must be between ages 18 to 65 and have suffered a complete motor-spinal cord injury below the cervical spine level 4. Patients with certain illnesses and injuries may be excluded by the trial's rigid guidelines.

Shapiro said the weak electrical field generated by the battery-powered device - about 600 microvolts per millimeter - mimics that which promotes rapid growth in human and animal embryos.

He said the stimulator, which is about the size of two joined lipstick cases, will be removed after 14 weeks of stimulating the tissue. The device has six electrodes radiating from it, three of which are placed above the spinal injury site, and three below it.

Because nerve growth occurs only when bathed in a negative electrical field, the direction of the current flow is reversed every 10 or 15 minutes so that nerves grow toward each other, closing the gap, said Richard Borgens, director of Purdue's Center for Paralysis Research.

Borgens and his colleagues began work on the oscillating field stimulator in the late 1980s. The device was first tested on dogs with natural cases of paraplegia in the early 1990s, but it has since been fine-tuned in anticipation of human trials.

In the series of dog trials performed to date, about 85 percent of the canines showed improvements in their bodily functions. A few even regained the ability to walk, said Borgens, a professor of developmental anatomy.

He said adapting the device for use in humans couldn't have been possible without $2 million in state funding approved in 1999 for the joint Purdue-Indiana University initiative. Researchers from the two schools are working on a number of other potential treatments for paralysis.

During the announcement, one of the dogs successfully treated during the Purdue animal tests roamed the stage as his owners described how their beloved 7-year-old dog, Yukon, was able to walk again when he was treated by Borgens' team following a 1996 injury that paralyzed the canine's hindquarters.

Then came 19-year-old Nichole Richards of Indianapolis, who was paralyzed in a car crash and wept as she described how her life had changed since the accident left her in a wheelchair and with limited use of her arms.

"What's going on here is making all of us anxious and excited and we hope that what they've been able to do with dogs they will eventually be able to do with humans," she said.

Richards, a former gymnast who had dreamed of being part of Ball State University's women's gymnastics team, is not a candidate for the Purdue-IU clinical trial because her injury occurred in February.

The joint initiative is one of a handful under way worldwide, including the controversial transplantation of fetal spinal cord tissue into patients, said Naomi Kleitman, education director for the Miami Project to Cure Paralysis.

If any of those therapies prove successful, they will add to the limited "tool box" of therapies doctors can dip into to treat the wide range of spinal cord injuries, as well as related trauma such as head injuries, said Kleitman, an adjunct associate professor of neurosurgery at the University of Miami's School of Medicine.

"The fact they they're going to a clinical trial in Indianapolis is very exciting and it's good evidence that the field has made progress, but obviously we have to be realistic. There's no guarantee any of this will work in humans," she said.

During the announcement of the Purdue-IU study, the chairwoman of the Indianapolis Motor Speedway said she is donating $2.7 million to the two schools to create endowed professorships aimed at promoting further paralysis research.

Mari Hulman George, a dog lover known for her work saving abandoned greyhounds, said her main motivation in making the donation was a spinal injury her grandson, Jarrod, suffered in a bicycle accident when he was nine.

Although he eventually recovered from his paralysis and is now a healthy 18-year-old college student, she said spinal cord research is crucial to the roughly 10,000 Americans paralyzed each year.

"My hope," George said, "is that the results of this research will improve the lives of the ones we love the most - both human and animal."